Wang Siqi, Zhang Zhaohuan, Malakar Pradeep K, Pan Yingjie, Zhao Yong
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China.
Front Microbiol. 2019 Jul 16;10:1614. doi: 10.3389/fmicb.2019.01614. eCollection 2019.
causes the most seafood-attributed gastroenteritis outbreaks worldwide and studies on its pathogenesis during passage through the human digestive fluids are limited. An continuous model system mimicking passage through saliva, gastric and intestinal fluid was used to study the survival, morphology and virulence-related gene expression of a total of sixty pathogenic, and non-pathogenic strains. The changes to these three characteristics for the sixty strains were minimal on passage through the saliva fluid. No strains survived passage through gastric fluid with low pH values (2.0 and 3.0) and the cells, examined microscopically, were severely damaged. However, when the pH of gastric fluid increased to 4.0, the bacterial survival rate was 54.70 ± 1.11%, and the survival rate of pathogenic strains was higher when compared to non-pathogenic strains. Even though the bactericidal effect of intestinal fluid was lower than gastric fluid, virulence-related gene expression was enhanced in the intestinal fluid. Seafood matrices can significantly raise the pH level of gastric fluid and thus aid the survival of through passage from human gastric acid and progression of pathogenesis in the intestinal fluid. We confirmed these phenomena in the continuous digestion model.
它在全球范围内导致了大多数由海鲜引起的肠胃炎暴发，而关于其在人体消化液中传播过程中发病机制的研究有限。使用一个模拟通过唾液、胃液和肠液的连续模型系统，研究了总共60株致病性和非致病性菌株的存活情况、形态以及与毒力相关的基因表达。这60株菌株在通过唾液时，这三个特征的变化很小。没有菌株能在低pH值（2.0和3.0）的胃液中存活，显微镜检查发现细胞受到严重损伤。然而，当胃液pH值升至4.0时，细菌存活率为54.70±1.11%，与非致病性菌株相比，致病性菌株的存活率更高。尽管肠液的杀菌作用低于胃液，但在肠液中与毒力相关的基因表达增强。海鲜基质可显著提高胃液的pH值，从而有助于其在通过人体胃酸后存活，并在肠液中促进发病机制的进展。我们在连续消化模型中证实了这些现象。
